The basic search capabilities of MediaWiki (at least, the version we're running - 1.7.1) are pretty poor. I'd like to improve them with an extension, but there are a lot of options and I'd like to have a good starting point.
For what it's worth, the wiki is an internal one; we don't have the option, for example, of using the Google search extension, because it's not going to be able to crawl the wiki's contents. I need a solution that will run entirely on the wiki server.
Here are the wiki version details:
MediaWiki: 1.7.1
PHP: 5.2.8 (apache2handler)
MySQL: 4.1.21-log
What are my options?